1. Field of the Invention
The present invention relates to fast drying, water permeable padding, which is utilized in any immobilization apparatus, in particular, an apparatus and method is disclosed for casting or immobilizing any part of a human or animal anatomy.
2. Description of Related Art
There are many types of padding materials currently used under rigid casts or other immobilization apparatuses. These traditional padding materials include cotton, rayon, polyester, polypropylene and other types of synthetic materials. In one method of applying a rigid cast, a tube of stockinet is first applied to the limb followed by a layer of padding. An immobilizing material is next applied on top of the padding and consists of either a Plaster of Paris impregnated substrate, a polyurethane-coated substrate or any other type of bracing or splinting material. Traditional cast underpad is supplied in rolls in widths from 2 to 6 inches. The purpose of underpad is to provide cushioning of the limb and to maintain conformity against the limb so as not to form folds or creases against the skin which could result in sores or infection. The immobolizing material or cast applied on top of this padding is usually made of plaster of paris or polyurethane-coated fiberglass. The open structure of the immobilizing material outer layers, however, will allow some water to pass through and be absorbed into the traditional padding materials underneath. If the padding becomes wet, it would take many hours to dry, if not days. In addition, skin maceration could occur which can lead to infection by bacteria or fungi. The probability for these types of complications is much greater in pediatric, geriatric, and circulatory impaired patients where the patient is unable to convey their symptoms which results in delayed and prolonged treatment. Furthermore, it is important for the padding to stay dry and have enough “fluffiness” or loft to allow the moisture vapors that are created from perspiration or other sources to be transmitted outwards through the padding.
Some cast padding manufacturers advise the wearer to dry the padding with a hair dryer, should it become wet, to try and avoid these skin related problems. Drying can take several hours and patient compliance is difficult to achieve. Since casts are usually worn for periods ranging from a few weeks up to several months, the wearer is constantly faced with the challenge of maintaining their personal shower or bath routine without getting their cast wet. Some wearers resort to wrapping their limb in a plastic bag so they can take a shower. This approach is cumbersome and doesn't always work that well due to leakage of the seal area. All padding used in conventional casting procedures is “breathable” to a certain extent. “Breathable” can be defined as padding's ability to allow air and/or moisture vapor from body perspiration to pass through it. When water is added to conventional padding on the market today, it tends to compress or “wad up”. Moreover, water saturated padding will not allow for effective transfer of moisture away from the skin and will lead to skin maceration if the wet padding is worn for extended periods of time.
Prior art approaches to “breathable”, self-drying padding for casting applications include U.S. Pat. No. 5,277,954 which discloses “an adhesive-backed layered composite of padding between two layers of water impermeable, moisture-vapor-permeable film, preferably porous, expanded polytetrafluoroethylene”. This product does not allow water to pass through it, but is designed to allow for moisture vapor transmission only. U.S. Pat. No. 5,016,622 discloses an “inner liquid water impermeable, water vapor permeable protective sleeve next to the skin” over which regular types of cast padding can be placed”. This two step approach is intended to perform the same basic function as U.S. Pat. No. 5,277,954, except that the product does not have a unitized construction. U.S. Pat. No. 5,380,260 discloses “a moisture vapor permeable, water impervious padding including sheets or strips of lofted non-woven fabric having wax, silicone resin or fluorinated polymer at a surface layer thereof”. Finally, U.S. Pat. No. 5,720,714 discloses “a first moisture vapor permeable film layer and a second moisture vapor permeable film layer with air bubbles spaced in between”.
The use of cast paddings having a “water impermeable, moisture-vapor-permeable film”, as indicated in the four preceding patents, can result in a squishy or water logged feeling against the skin, immediately after the cast is immersed in water. The inherent properties of the moisture vapor permeable films utilized in these designs tend to “trap” any water against the skin until it can be vaporized by normal body temperature. The “water logged” sensation associated with these water impermeable barriers can continue for 45 minutes and beyond, until body heat begins to vaporize the trapped water between the barrier and the skin. The padding systems of the prior art rely on water impermeable and moisture permeable films to achieve their end effect, and do not maximize water runoff underneath the cast or brace.
It is therefore an object of the present invention to provide a water permeable padding design that channels water away from a cast or other immobolizing device.
It is a further object of the present invention to provide a padding for a cast that can be flushed with various solutions for cleansing of the limb beneath while avoiding the accumulation of excess moisture.
It is a further object of the present invention to provide a padding in combination with an orthopedic cast material that can be immersed in water then dried quickly in the open air.
It is a further object of the present invention to provide a padding in combination with an orthopedic cast material with quick drying features as well as improved skin comfort immediately after getting the cast wet.
It is a further object of the present invention to provide a cast that allows for effective transfer of moisture away from the skin thereby avoiding skin maceration.